A weapons-grade ring of electrorefined plutonium, typical of the rings refined at Los Alamos and sent to Rocky Flats for fabrication
. Source. The ring has a purity of 99.96%, weighs 5.3 kg, and is approx 11 cm in diameter. It is enough plutonium for one bomb core. Which city shall we blow up today?Ciro Santilli is mildly obsessed by nuclear reactions, because they are so quirky. How can a little ball destroy a city? How can putting too much of it together produce criticality and kill people like in the Slotin accident or the Tokaimura criticality accident. It is mind blowing really.
More fun nuclear stuff to watch:
- Dr. Strangelove (1964)
- en.wikipedia.org/wiki/Chernobyl_(miniseries)
- The World Of Enrico Fermi by Harvard Project Physics (1970)
- Fat Man and Little Boy (1987) shows a possibly reasonably realistic of the history of the development of the Trinity
The Ultimate Guide to Nuclear Weapons by hypohystericalhistory (2022)
Source. Good overall summary. Some interesting points:- youtu.be/8uIPQBOCJ64?t=2946 talks about the difference between tactical and strategic nuclear weapons
- youtu.be/8uIPQBOCJ64?t=3291 mentions variable yield devices, this is the main new thing Ciro Santilli learned from this video
- youtu.be/8uIPQBOCJ64?t=3416 discusses if a strategic nuclear weapon usage would inevitably lead to tactical nuclear weapon escalation. It then mentions one case in which a possibly comparable escalation didn't happen: the abstinence of using chemical weapon during World War II.
- Stack Exchange's censorship of "I think Trump is disgusting as a person" from Ciro Santilli's profile: cirosantilli.com/china-dictatorship/sstack-overflow-forbids-criticizing-the-character-of-genocidal-political-leaders-like-xi-jinping
This is particularly important in SQL: Nested set model in SQL, as it is an efficient way to transverse trees there, since querying parents every time would require multiple disk accesses.
The ASCII art visualizations from stackoverflow.com/questions/192220/what-is-the-most-efficient-elegant-way-to-parse-a-flat-table-into-a-tree/194031#194031 are worth reproducing.
As the sets:
__________________________________________________________________________
| Root 1 |
| ________________________________ ________________________________ |
| | Child 1.1 | | Child 1.2 | |
| | ___________ ___________ | | ___________ ___________ | |
| | | C 1.1.1 | | C 1.1.2 | | | | C 1.2.1 | | C 1.2.2 | | |
1 2 3___________4 5___________6 7 8 9___________10 11__________12 13 14
| |________________________________| |________________________________| |
|__________________________________________________________________________|Consider the following nested set:
0, 8, root
1, 7, mathematics
2, 3, geometry
3, 6, calculus
4, 5, derivative
5, 6, integral
6, 7, algebra
7, 8, physicsPreviously on EdX: www.edx.org/learn/quantum-physics-mechanics/delft-university-of-technology-topology-in-condensed-matter-tying-quantum-knots "DelftX: Topology in Condensed Matter: Tying Quantum Knots".
But then they regained their sanity and put the source code on GitHub: github.com/topocm/topocm_content and is CC BY-SA.
- Google Maps download offline maps. This works very reliably, you can select the area you want to download. The only downside is that Google maps can't reliably show a route offline, and it does not contain national cycle route routes. Or those features are impossible for a software engineer to get working after trying for about 2 hours.
- OpenStreetMap on browser with cycling layer: www.openstreetmap.org/#map=5/49.582/1.934&layers=C This is the best visualization of cycling routes I've found so far, contains both National Cycle Network and National Byway and a few others, and they are shown extremely clearly. But as a website it doesn't reliably work offline
- the OsmAnd app for Android is the best offline free-ish OpenStreetMap viewer I've found so far. You only have to pay after reaching 5 region downloads, and it is very cheap if you want to do so. The cycle route view is not amazing, the routes are not so clearly marked and mixed with very similarly colored big roads, but with a bit of effort you can make them out. No routing though
- I've heard Komoot can keep a predefined route (possibly auto planed) reliably offline, but haven't used it myself. I was not able to see National Cycle Route clearly marked anywhere on it
These minorities actually had different legal statuses, e.g. they were exempt from the One Child Policy.
Manuals: si.shimano.com/
Overview of Shimano brands 2018: www.evanscycles.com/coffeestop/advice/the-complete-guide-to-shimanos-mountain-bike-groupsets-and-their-hierarchy
- Shimano Altus RD-M310: almost cheapest MTB
- Shimano Acera RD-M360: second cheapest MTB
- Shimano Alivio RD-M410: third cheapest MTB
- Shimano Claris: entry 8-speed road bike www.youtube.com/watch?v=6dFQDDg6Wt0
- Shimano Sora: 9-speed road bike bike.shimano.com/en-EU/product/component/sora-r3000.html
- Shimano Tiagra: 10-speed road bike bike.shimano.com/en-EU/product/component/tiagra-4700.html
- Shimano Deore: non-shitty MTB, in increasing performance: M610, M6000, M7000, ...)
- Shimano Tourney; commuter, likely the shittiest of all lines: bike.shimano.com/en-EU/product/component/tourney.html
Pinned article: Introduction to the OurBigBook Project
Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
Intro to OurBigBook
. Source. We have two killer features:
- topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculusArticles of different users are sorted by upvote within each article page. This feature is a bit like:
- a Wikipedia where each user can have their own version of each article
- a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
Figure 1. Screenshot of the "Derivative" topic page. View it live at: ourbigbook.com/go/topic/derivativeVideo 2. OurBigBook Web topics demo. Source. - local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
Figure 2. You can publish local OurBigBook lightweight markup files to either OurBigBook.com or as a static website.
Figure 3. Visual Studio Code extension installation.
Figure 5. . You can also edit articles on the Web editor without installing anything locally. Video 3. Edit locally and publish demo. Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension. 
- Infinitely deep tables of contents:
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact